A revised version of IEEE 43 was published on March 6, 2014, which replaces the previous IEEE 43:
2000 edition. The working group that developed this new version of IEEE 43 was chaired by Mr. Ian
Culbert of Qualitrol ‐ Iris Power. This standard is one of the most widely used IEEE standards in the
power equipment field. The working group to revise IEEE 43 had more than 40 experts from around
the world, and it took over 5 years to complete its work. IEEE 43:2013 is likely to be the basis of a new
IEC standard on insulation resistance and polarization index testing. Greg Stone, also of Qualitrol ‐ Iris
Power, is the convenor of this new IEC working group.
The major changes included in the new version of IEEE 43 are as follows;
Revision of Figure 1 – Equivalent Circuit to better reflect the characteristics of the absorption cur‐
rent that flows during an insulation resistance test.
Information on the effects of stress control coatings on both insulation resistance (IR) and polariza‐
tion index (PI) measurements.
Provision of different IR temperature correction factors for thermoplastic, e.g. asphaltic mica and
thermosetting, e.g., epoxy mica insulation systems.
More detailed guidelines on the interpretation of PI measurements for AC machine rotor and DC
machine armature windings.
The addition of a new Annex C providing information on the identification of some types of wind‐
ing insulation degradation from the analysis of charge and discharge current profiles, as can be
obtained from the PDTech DRA3 instrument.
Recognition that stator windings which have their complete overhang treated with voltage stress
control material will have a PI close to 1.0 and that surface tracking may develop in such windings.
A new Annex D which gives a brief introduction to insulation resistance profiling. This technique
involves interpreting the condition of a stator winding insulation system from the shape of a 10
minute PI test profile. The IEEE 43 working group did not feel that this technology was sufficiently
advanced to include details of it in the standard itself.
There were no significant changes made on how to interpret IR and PI results.§